---
title: "Fly.io"
description: "Deploy Fabro to Fly.io from the prebuilt GHCR image, with a Fly Volume for state"
---

<Warning>
  The server interface is in private early access. Contact [bryan@qlty.sh](mailto:bryan@qlty.sh) if you're interested in trying it.
</Warning>

[Fly.io](https://fly.io) can host the Fabro server by pulling the pre-built image published to GHCR. The repo ships a `fly.toml` that points Fly directly at the image — no build step on Fly's builders, no `Dockerfile` evaluation — and declares a Volume mount at `/storage` so your runs, checkpoints, and sessions survive redeploys.

Fly.io is CLI-first; there is no one-click deploy button. The workflow below uses [`flyctl`](https://fly.io/docs/flyctl/install/).

## First-deploy checklist

### 1. Adopt `fly.toml` in a new app

```bash
git clone https://github.com/fabro-sh/fabro
cd fabro
fly launch --copy-config --no-deploy
```

`fly launch --copy-config` keeps the repo's `fly.toml` instead of generating a new one; `--no-deploy` lets you finish wiring secrets and volumes before the first deploy. You'll be prompted for an **app name** (must be globally unique on Fly) and a **primary region** — update `fly.toml` in place if you change the defaults.

### 2. Create the persistent Volume

Fabro writes all persistent state — run history, checkpoints, sessions, the default token, and JWT keys — under `/storage`. Fly containers have ephemeral filesystems, so without a Volume that directory is wiped on every redeploy. `fly.toml` declares the mount but **cannot create the volume itself** — provision it with `flyctl`:

```bash
fly volumes create storage --size 1 --region <your-primary-region>
```

Grow later with `fly volumes extend` if needed. The volume name (`storage`) must match `[[mounts]].source` in `fly.toml`.

### 3. Set required environment variables

Fly stores env vars as encrypted secrets:

```bash
fly secrets set \
  ANTHROPIC_API_KEY=... \
  SESSION_SECRET=...
```

The [Server Configuration](/administration/server-configuration) reference has the full list; the minimum useful set:

| Variable | Purpose |
|---|---|
| `ANTHROPIC_API_KEY` / `OPENAI_API_KEY` / `GEMINI_API_KEY` / ... | At least one LLM provider key for the models you'll run |
| `FABRO_DEV_TOKEN` | Optional — pre-set the dev token instead of reading the one written to `/storage` on first boot |
| `SESSION_SECRET` | 64-character hex string; required when the web UI is enabled |
| `GITHUB_APP_CLIENT_SECRET`, `GITHUB_APP_WEBHOOK_SECRET`, `GITHUB_APP_PRIVATE_KEY` | Only if you enable GitHub OAuth or the GitHub App integration |

### 4. Deploy

```bash
fly deploy
```

Fly pulls `ghcr.io/fabro-sh/fabro:nightly`, attaches the volume, and starts the Machine. The health check on `/health` must pass before traffic is routed.

## Accessing your Fabro server

Once the deploy is healthy, Fly exposes a `<app>.fly.dev` URL (or your custom domain). Two things to grab:

1. **The dev token** — on first boot, Fabro writes one to `/var/fabro/dev-token` and logs it. Read it via the Machine's shell:

   ```bash
   fly ssh console -C "cat /var/fabro/dev-token"
   ```

   Or tail the startup logs with `fly logs`.

2. **Point your local CLI at the server** — add the Fly URL to `~/.fabro/settings.toml`:

   ```toml title="~/.fabro/settings.toml"
   [cli.target]
   type = "http"
   url = "https://<your-app>.fly.dev/api/v1"
   ```

   Then commands like `fabro model list --server <url>` will hit your Fly instance.

See [Running the Fabro Server](/administration/deploy-server) for the full auth and CLI-pointing story.

## Redeploys and updates

`fly deploy` re-pulls the GHCR image on every run. `fly.toml` references the `:nightly` tag by default, so redeploying picks up the latest nightly automatically. To pin a specific version, edit `fly.toml` to reference `ghcr.io/fabro-sh/fabro:<version>` and redeploy. The `/storage` Volume survives redeploys, so runs and checkpoints persist.

## Caveats

- **`$PORT` is not injected.** Unlike Railway and Render, Fly does not set a `PORT` environment variable. The Fabro image binds to `$PORT` if set, otherwise `32276` — `fly.toml` pins `internal_port = 32276` so the default works. If you change `internal_port`, also `fly secrets set PORT=<n>` to match.
- **Volume is load-bearing and not replicated.** Fly's docs recommend at least two Volumes per app for redundancy, but Fabro's server is single-replica by design — one Machine owns `/storage`. Treat this like a traditional VPS: hardware failure means restoring from [Fly's volume snapshots](https://fly.io/docs/volumes/snapshots/) or a backup you manage.
- **Single Machine.** Don't `fly scale count` above 1 — a second Machine can't mount the same Volume, and the server assumes a single writer.
- **Architecture.** Fly Machines run x86_64 (amd64) by default. The `:nightly` tag is multi-arch, but the arm64 variant is not currently usable — stay on amd64.
- **Autostop is disabled.** `fly.toml` sets `auto_stop_machines = "off"` so the Machine stays up for the run queue. Leaving autostop enabled would pause Fabro when there's no HTTP traffic, stalling any in-flight runs.

## Next steps

<Columns cols={2}>
  <Card title="Running the Fabro Server" icon="server" href="/administration/deploy-server">
    Auth, dev tokens, submitting runs, and pointing the CLI at your deployment.
  </Card>
  <Card title="Server Configuration" icon="gear" href="/administration/server-configuration">
    Full `settings.toml` reference — TLS, auth methods, concurrency, and more.
  </Card>
</Columns>